This invention relates to a device for relieving tension-loaded servomotors employed for the height adjustment of cantilever arms, particularly the cantilever arms of open-pit mining equipment. The apparatus includes at least one pulling member being connectable in parallel with the servomotor or servomotors.
Cantilever arms of machines such as open-pit mining equipment, cranes and similar conveying devices often include tension-loaded servomotors for height adjustment, particularly hydraulic cylinders. If--for example, in the case of a malfunction--the servomotor must be replaced, the problem is encountered that before the servomotor can be relieved of the tension load, the cantilever arm must be fixed in its position. This is customarily effected by a supporting framework which supports the cantilever arm or, as the case may be, the heavier counterweight cantilever arm against the ground. It is a disadvantage of such a method that it requires significant material input, it is time-consuming and it is not reliable.
Instead of a supporting framework, as outlined above, additional guying has been employed by attaching a tension cable parallel to the servomotor so as to absorb the tensile forces after the servomotor has been relieved of loads. In order to avoid damage to the hydraulic cylinder, the cable must be disposed at a sufficient distance from the latter. Fastening of the cable generally proves difficult because special and sufficiently stable attachment means, for example eye straps, are not available or cannot be applied. Moreover, the cable must also be provided with suitable attachment means and must have a defined length.